Add option text to README

Author: RadicalZephyr

README.md

@@ -4,10 +4,25 @@ A very simple command line program to send Windows Desktop Notifications.
 
 ## Usage
 
+### Example
+
 ``` batchfile
 > DesktopNotifier.exe -t Title -m "Hello, Notifications!"
 ```
 
+### Options
+
+```
+  -m, --message     Required. (Default: Hello, World) The message to display.
+
+  -t, --title       Required. (Default: Terminal) The title text to display.
+
+  -i, --icon        The path to a .ico file to display.
+
+  -s, --showTime    (Default: 10000) The length of time to show notification
+                    for in milliseconds.
+```
+
 ## License
 
 Copyright 2016 Geoff Shannon